Before everyone decides to tell you use the "search" at the top right of the page i'll give you some of the infomation that you have over looked.
First, the CZ 858 fires the 7.62 x 39 mm round, not the 7.62 x 51 mm NATO which I imagine your thinking of. Both are extremely different and obviously are not interchangable. So i advise to brush up on you bullet caliber information first.
Secondly, the AR180-2 is hard to come across (as i hear) while the CZ-858 is commerically avaiable from alot of places. Also if you look at the top of the black rifle section there is a sticky dealing with the AR180B and a sticky of the CZ-858 in the red rifle section. Both include stuff on how they function, break-down procdures, common problems, how to guides etc. etc. READ THEM NOW
And thirdly, how far is long range? No one can give much information from just those two words. 300 meters? 500 meters? 1 kilometer?
FYI, feel lucky that i answered first before fellow CGNer's decided to rip you to shreds. I can only suggest various reading threads until you eyes bleed....... it seems to work for me.